Abstract
Water retaining concrete structures, specifically reinforced concrete, experience extensive damage due to repeated chemical and physical attack. This attack includes permeation of chlorides and sulfates and stimulates subsequent corrosion of reinforcing steel and soft water attack due to flowing of water and water processing. The recurring cycles of steel corrosion, passivation, and depassivation causes expansion resulting in concrete cracking, delamination, and spalling. The resulting damage leads to shortened concrete life-span and constant demand for repair and replacement of water retaining concrete structures. This research endeavor examined the impact of chloride penetration and depth of water penetration on treated concrete samples. A novel hydrogel technology that has been shown to improve overall concrete durability was compared to a reference mixture to determine the resistance to chemical and physical attack. Hydrogel technologies have been shown to chemically alter the surface and sub-surface of the concrete. This chemical reaction produces more of the backbone of concrete strength, calcium-silicate-hydrate (C-S-H), within the pore structure while reducing or immobilizing the lime, soluble alkalis, and other deleterious materials in the concrete pore solution. Additionally, the rapid formation of the hydrogel physically takes up space within any localized damaged areas inside the concrete to further prevent percolation on the damaged concrete. Ultimately it was shown in laboratory testing that hydrogel technology can be used to increase concrete resiliency to steel corrosion, extend the concrete life of water retaining structures, and reduce the need for premature repair and replacement.
Keywords: Water, Hydrogels, Corrosion, Service-Life
Authors: Doug Hamlin, Mallory Westbrook, Martin Prestidge, and Jon S. Belkowitz
Published by Water New Zealand 22 February 2022.